Removal of the long-lived 222Rn daughters from steel and germanium surfaces

Removal of the long-lived 222Rn daughters (210Pb, 210Bi and 210Po) from stainless steel and germanium surfaces was investigated. As cleaning technique etching was applied to samples in a form of discs exposed earlier to a strong radon source. Reduction of the 210Pb activity was tested using a HPGe spectrometer, for 210Bi a beta spectrometer and for 210Po an alpha spectrometer was used. According to the conducted measurements all the isotopes were removed very efficiently from germanium. Results obtained for stainless steel were worse but still better than those achieved for copper.